1. Field of the Invention
The present invention generally relates to an online karaoke system for distributing karaoke data having an identification code from a center station or a broadcasting center supplied with karaoke data from the center station to a plurality of karaoke terminals or sub host stations through a broadcasting communication network.
2. Description of Related Art
Online karaoke systems are known in which a center station holding a karaoke database supplies karaoke data through a public network or the like to karaoke terminals installed in a karaoke bar or the like or to a sub host station upon request from the karaoke terminals or sub host station. With the karaoke systems of this type, line usage fee is charged every time karaoke data is transmitted from the center station to each karaoke bar. Therefore, as the number of karaoke bars increases, so does the number of times at which karaoke data is transmitted, thereby presenting a problem of increased communication cost.
On the other hand, a broadcast online system is known in which data is broadcast from a key station to sub stations through a communication satellite. This system has an advantage in its suitability for efficiently distributing the same type of data to many sub stations. With the recent rapid drop in communication cost, the broadcast data communication system has been extensively put into operation in various fields.
The above-mentioned broadcast data communication technology may be applied to efficient and low-cost distribution of karaoke data in an online karaoke system connected to many karaoke terminals. However, the broadcasting of karaoke data from the center station involves a problem that a karaoke terminal not ready for receiving karaoke data or suffering from reception error caused by unfavorable weather receives defective karaoke data and has no means for receiving retransmission of correct karaoke data.
To overcome this problem, karaoke data may be broadcast repeatedly. However, this method requires the karaoke terminals or sub host stations that receive the karaoke data to keep their hard disk drives for storing the karaoke data in an accessible state until the karaoke data can be correctly received. Keeping the hard disk drives running this way is a waste of electric power and quickens their deterioration.
The transmission power of the satellite broadcasting for use in the broadcast communication is extremely high. Therefore, while the karaoke terminals or sub host stations can receive karaoke data, the capability of storing the received karaoke data into a buffer may not be so high for the data transmission. In addition, insufficient buffer capacity or insufficient transfer rate of data to the hard disk drive may make the buffer be filled up with the received karaoke data before the data transfer from the buffer to the hard disk drive is completed. On the other hand, lowering the performance of the karaoke data transmission compels the karaoke terminals or sub host stations that have enough buffer capacity to work unnecessarily for a protracted period, which is a waste of electric power and quickens hard disk drive deterioration.